Two sisters, just seven and five years old, are starring in a film aimed at saving people's lives. The short documentary follows the girls around the 2006 International AIDS conference in Toronto, as they talk to those at the vanguard of the fight against the pandemic. Malcolm Brown has the story.

Seven-year-old Vineeta Hennessey and her five-year-old sister Sevilla are in the spotlight for a documentary called "Please Talk to Kids About AIDS".

In it, experts and activists face questions that only a child would ask.

Vineeta asked, "How does AIDS get into your body?'" A doctor responds, "Well, AIDS gets into your body in ways that can be complicated to explain to little girls!"

That gets a laugh from the audience at Johns Hopkins University's School of Public Health.

But the girls also elicit frank responses from leading experts, such as prize-winning science writer Laurie Garrett. She explains, "What's sneaky about the AIDS virus is that, guess what it infects, what kinds of cells it goes inside of? The immune cells. So, the army you have inside of you to protect you is exactly where this virus goes…."

That sort of jargon-free language has drawn attention to the film. There is also praise for the way it breaks taboos about discussing sex. A doctor explains what a sex worker is. She says, "A sex worker is someone who gives sex services to another person in exchange for money…"

In spite of the film's subject matter involving prostitution or condoms, the girls are supported by their parents -- both international public health advocates.

"To have children, in their innocence, ask those questions and really force people to give a straight answer to this, I think really exemplifies why we need to talk straight about HIV," Dr. Fauci said.

The documentary's young stars are promoting the film and discussing the answers they got.

Vineeta offering her reaction, says, "Some of them were real difficult -- like sexual. I was like, 'Whoa, what is that?'"